Many countries require new vehicles to include an immobilizer device in ignition circuitry of the vehicles. An immobilizer is a security system, typically made up of an immobilizer base station and a transponder in a key. The immobilizer base station is typically located in the steering column or in the dashboard of a vehicle and is able to prevent fuel flow or ignition of the vehicle (i.e., by breaking an electrical circuit or otherwise disabling signal flow within the circuitry of the vehicle) when the key is not present. Properly configured, an immobilizer can greatly reduce the possibility of vehicle theft because standard hotwiring methods are ineffective.
A transponder may be a legacy transponder using load modulation (LM) communication method. A LM type transponder offers limited range. New type of transponders use charge & talk (C&T) communication method and offer extended range of communication. A transponder designed to work with C&T base station is not able to communication with legacy LM base stations and vice versa.